LISP help

[Anonymous]

Hello!

I have this lisp routine, that creates a line, then asks for objects to stretch to that line, and then deletes said line. Simple and elegant:

(defun c:q5()
     (command "line" pause pause "")
     (setq e1 (entlast))
     (command "extend" e1 "_CP" "" pause pause "")
     (command "erase" e1 "" "")
     (princ)
 )

So the way it operates, one can only extend two objects before it ends the command and then comes up with "Unknown command "Q5". Press F1 for help." on the command line. How can I make the command continue asking for objects to extend indefinitely and also prevent that "Unknown command" message?

I added a screencast showing what I described. Of course, I pressed shift to trim instead of extend on the second object.

Thank you!

[pbejse · Accepted solution]

(defun c:q5()
     (command "line" pause pause "")
     (setq e1 (entlast))
     (command "extend" e1 "_CP" "")
	  (while (> (getvar "CMDACTIVE") 0)
	  (command pause)
	)
     (command "erase" e1 "")
     (princ)
 )

[Anonymous]

Great! Thank you for the help!

-Michael

[Anonymous]

So the "while" function works like this:

If the value of the system variable CMDACTIVE (meaning there is currently a command active?) is greater than 0 (meaning 1?) then the command will pause indefinitely?

I am VERY new to AutoLISP and have no other coding experience. It is interesting and exploring LISP I have found some SUPER handy codes and even created a few simple ones by analyzing others.

Thanks a bunch!

Michael

[ВeekeeCZ · Accepted solution]

The code has some lacks... 

When selecting edge(s) you need to close the selection since a multiple selection is allow. 

Then not sure if you need to specify CP type of selection... doesn't work that without it too?

(defun c:q5 ( / e1)
  (command "line" pause pause "")
  (setq e1 (entlast))
  (command "extend" e1 "") 
  (while (> (getvar "CMDACTIVE") 0)
    (command pause))
  (command "erase" e1 "")
  (princ)
  )

BTW using 'cmdactive is, I would say, the 'traditional' way. Since version 2015 we could use the following trick that works the same. The COMMAND-S somehow keeps the user within the command until he decides to finish it.

(defun c:q6 ( / e1)
  (command "line" pause pause "")
  (setq e1 (entlast))
  (command-s "extend" e1 "")
  (command "erase" e1 "")
  (princ)
  )

[Anonymous]

It looked like there was a "" (close) on the extend command already, after the "_CP", which I'm not sure about why it was in there, but you're right, doesn't seem necessary. I'll give it a try!

Thanks,

Michael